#bigbox{
	width: 500px;
	height: 500px;
	border: 1px solid black;
	position: relative;
	margin-left: auto;/*在positon是相对属性之下，设置界面左右居中特性*/
	margin-right: auto;
}
#bigbox>a{
	width:100px;
	height: 100px;
	border: 1px solid black;
	background: pink;
	display: block;/*line-block 既有行级又有块级*/
	color: white;
	font-weight: bolder;
	text-align: center;
	font-size: 36px;
	line-height: 100px;
	text-decoration: none;
}
#bigbox>a:nth-child(1){
	position: absolute;
	right: 10px;
	top:   10px;
}
#bigbox>a:nth-child(2){
	position: absolute;
	right: 10px;
	bottom:10px;
}
#bigbox>a:nth-child(3){
	position: absolute;
	left: 10px;
	top:   10px;
}
#bigbox>a:nth-child(4){
	position: absolute;
	left: 10px;
	bottom:   10px;
}
#bigbox>a:nth-child(5){
	position: absolute;
	top: 190px;
	bottom:   190px;
	right: 190px;
}
#bigbox>a:hover{
	background: blueviolet;
}
